Metastatic chondrosarcoma, patterns of care, and outcomes of patients in a real-life national setting over a decade.

Metastatic chondrosarcoma (MCS) has a poor prognosis, and treatment options are scarce in this rare disease. This multicenter observational study provides real-world data on treatment patterns of patients with MCS in France. Treatment characteristics, outcomes in terms of time to next treatment (TTNT) and overall survival (OS), and prognostic factors of patients ≥12-year-old treated for a MCS in nine French reference network centers were retrieved from the French Sarcoma Group prospective database. From 2008 to 2018, 127 patients with MCS were included, 31 were metastatic from diagnosis (synchronous cohort), 89 had a metastatic relapse, and 7 had locally advanced unresectable disease, of whom 4 developed secondary metastases (metachronous cohort). Median age at diagnosis was 61 years (14-90), 58.9% of patients received a systemic treatment with a median of 2 lines (1-6), 40.3% had a locoregional procedure on metastasis, and 9.7% of patients participated in a clinical trial at least once in the metastatic setting. Median OS from metastatic diagnosis was 12.7 months [95%CI 8.2, 14.9], without significant difference between the metachronous and synchronous cohorts. Median TTNT was 4.6 months [95%CI 3.0, 5.9], 3.4 months [95%CI 2.7, 4.8], and 3.4 months [95%CI 2.0, 7.9] in first, second, and third lines, respectively. In MCS, benefits of chemotherapies are very limited. Tyrosine kinase inhibitors such as regorafenib or pazopanib show some activity from first line. Locoregional treatment of metastasis is associated with survival and should be proposed when feasible. Inclusion in clinical trials should be prioritized.